Electrolysis



MA A. ADAM, J. STEVENSON, A. T. IVIABBITTI AND J. FIELDHOUSE.

ELECTRDLYSIS.

APPLICATION FILED AuG.3l. |920.

1,365,140. Patented Jan. 11, 1921.

lzwenazs:

' To all whom 'it may concern:

UNITED STATES Plan-:larI OFFICE. f

MATTHEW ATKINSON ADAM, JOHN STEVENSON, ALAN THOMAS HABBITT, AND JOHN FIELDHOUSE, 0F LONDON, ENGLAND; SAID STEVENSON,' SAID MABBITT, A N'D SAID FIELDHOUSE ASSIGNORS T0 SAID ADAM.

ELEcrnoLYsIs.

Specification of Letters Iatent. i

raeeneedaan. 11, 1921.1

Application-Med August 31, 1920. Serial No. 407,222'.

Be it known that we, MATTHEW ATKIN- soN ADAM, residing at 57 Lincolns Inn Fields, London, W. C. 2, England, JOHN STEvENsoN, residing at 28 Talbot road, Bayswater London, W. 2, England, ALAN THOMAS Manrr'r, residing -at 3 Wallwood road, London, E. 11, England, and JOHN FmLDHoUsE, residing at 2 Byield road, Walthamstow, London E., England, all subjects .of the King of Great Britain and Ireland, have invented certain new and useful Improvements Relating to Electrolysis, of which the following is a specificatlon.

This invention relates to the electrolyticdeposit of metals in non-coherent or loose crystalline form from solutions of metalllc salts in a cell or cells having a rotating cathode.

The object of the invention is to provide improved constructions or combinations-of apparatus for the above described purpose which enable improved practical results to be obtained.

The present invention, in brief, consists in the electrolytic deposition of metals in a non-coherent or loose crystalline form in a cellhaving a rotating cathode and employin a substantially uniform iiow of electro yte between the electrodes adapted to 1nsure applroximately uniform composition` within t e cell, and enable high current densities to be utilized.

Referring to the accompanying diagrammatic drawings,

Figure 1 re resents a transverse sectional view of one orm of construction of. rotating cathode cell according to the present invention; v

Fig. 2 is a similar view of a modification and Y Fig. 3 is a similar view of a.' further modification.

In carrying this Ainvention into eifect in one form, by way of example, as indicated in Fig. 1, as applied to the electrolytic recovery of tin from iron chlorid solutlons rich in tin and preferably rich in stannous,

chlorid as may be obtained by working the process described in our co-pend1n g application 407,250 correspondlng to Brltlsh application No. 4838 of 1919, we construct the cell c with two carbon anode bars a, b, preferably lof graphite which run the whole length ofthe cell. These are placed side by side, and hollowed outto form a trough of circular form concentric with the cathode drum cl. At the lowest point they are bored through at e to form exits for the electrolyte. The bars are hollowed out to form the trough, and a number of communicatin ways f of considerable width are formed a jacent to each upper edge or lip. These lips are grooved at g to receive a copper o r like bar h, which serves to supply current to the anode bars. Thel copper bars are bored and countersunk at intervals t receive bolts z' which pass down through the carbon bars a, b, and clamp ,them against a base board y' suitabl impre ated to prevent absorption of quid he communieating ways f are referably formed beneath the edge in order to prevent the electrolyte passing through them from coming into contact with the bars h, and for a similar reason the bolts z' are arranged to pass through the bars a, b, at solid sections between the communicating ways. Between the ,bars a, b, and the board y', is placed a rubber mat Z for jointing purposes. The end cheeks of the cell are provided with supports for the drum, and .are bolted against the ends of the carbon bars with` similar rubber mats not shown.A The longitudinal bolting ma be eiected by means of the copper bars in which case these project and are screwed to receive the clamping nuts not shown.

Outside of each yof the carbon barsvchambers m, n are formed to receive the electrolyte, and adjustable weirs o may be iitted along the edge of yeach carbon bar to regulate the How of electrolyte a uniform and evenly distributed How being aimed at asA far as possible.

The base board y' is formed with a central duct p and a number of channels g leading to an outside chamber r which discharges over an outlet Weir s of adjustable height. A

The cathode drum d is placed in position, andx is chosen of such a diameter as to leave a segmental annulus t of suitable width for the electrolyte. It i's also made longer than the anode bars, so as to extend beyond them at both ends. The electrolyte is supplied through inlet orifices made/say through the bottom of the cell, and flows over the inlet weirs o into the annular space t between the cathode and each of the anode bars. It then flows out through the bottom of the trough at e, and 'into the outlet chamber '11, where it passes over the outflow Weir s.

The cathode drum is rotated at a suitable rate in relation to the rate of flow of the electrolyte, and to the current density employed (see, for example, our application 407,250 correspondin to British application N o. 4838 of 1919 l.

A scraper plate lv extends across the drum, and is supported preferably on a chute w which receives the tin as it is delivered by the scraper. The tin receiving chute fw and scraper v are preferably mounted o'n hinges (not shown) so that they can be swung out of osition when desired.

t is found that this cell works well with a cathode current density of about 2.5 aniperes Aper square inch, the liquid flow and relative movement of cathode and electrol te being adjusted as therein indicated for the recovery of tin from a solution which has been employed to dissolve tin as described in our application 407,250.

This cell is applicable to the electro-deposition under considerable current. densities of all metals which under suitable conditions can be electro-deposited in loose or crystalline form.

According to a modified form of vconstruction, as illustrated in Fig. 2, the trough is formed by a graphite bar 20 hollowed out and provided with holes 21 along its base for exit of the electrolyte. The electrolyte passes into the trough cell from both sides over the edges of the graphite trough 20 from both sides 22 of the supply chamber and the exit passages 21 into a sump 23, whence it flows through a number of ways 24 to the outlet pipe 25.

The graphite bar is preferably impregnated with paraffiny wax to exclude the electrolyte from the pores thereof. Electricalv connection may be made conveniently by copper rods 2 passing through the end of the cell and entering the bar, care being taken that no access to this connection is possible by the electrolyte. Al convenient way of effecting good electrical connection 4is to drill a hole through the end wall of the cell penetrating partly into the anode, and to ram into this hole finely powdered carbon impregnated with paraffin wax, finally making connection with this rammed powder externally to the cell.

The drum cathode 26 is mounted upon a spindle above the trough 20 and thus mav be rotated during action o the cell with part oi its surface immersed in the electrolyte` the latter being caused to flow at a steady rate through the system. A. scraper 27 is arranged to collect the metallic tin from the surface of the drum.

A l'oim of construction including two cathodedrums is indicated in Fig. 3, in which the anodes are constructed of easily removable elements 1, 2 and A3, each independently clamped down on to a rubber inat- 4 by a series of set screws or similar clamping means in conjunction with copper connecting plates 5, 6 and 7. The two elements 1 and 3 are formed with sloping lower edges so that the element 2 will contribute y to hold them firmly in position.

Communicating Ways 8, 9 and 1() as in Fig. 1, are provided, but the electrolyte is in this case adapted to enter` simultaneously through 8 and 10, and pass via annuli 11 and 12 to the outlet 9 and flow pipe 13.

The two drums are rotated relatlvely in opposite directions as indicated by arrows. The. direction Qof rotation may be reversed,

but we prefer that this shall always be such that the periphery of the drums travel in the same direction as the flow'of electrolyte. Duets 18 and 19 are provided for draining off the electrolyte when required.

Sloping plates 14 and 15 are provided for conveying` the tin from the surface of the drums 3 and rotating wipers comprising say four rubber flaps 16 mounted to rotate on spindles 17. These wipers act to propel the tin along the plates 14 and 15, and prevent it from piling up at the edge of the plates.

We prefer to construct the rotating cathode of carbon impregnated with parafiin wax to enable the non-coherent metal readily to be removed and to mount it on its spindle so as to be removable readily therefrom for replacement.

Having now described our invention, what we claim as new and desire to secure by Letters Patent is 1. An electrolytic cell comprising a casing a rotatable cathode and a hollowed out anode in which the cathode may be rotated and suitable passages through the anode and casing for circulation of the electrolyte.

2. A cell such as claimed in claim 1 in which the cathode is a cylinder of carbon.

3. A cell such as claimed in claim 1 in which the hollowedout anode is provided with a Weir or weirs adjustable for deterniiiing the height of the electrolyte in the ce 4. A cell such as claimed in claim 1 provided with a scraper chute to remove the deposit from the cathode.

5. An electrolytic cell comprising a casing, a cathode and an anode, the anode and means of a rod or rods passing through casing having suitable passages thereboth 'anode and casing.

'throu h for circulation of the electrolyte. In testimony whereof we have signed our 6. cell such as claimed in claim 5 'havnames to this specification.

5 ing a Weir to regulate the height of the elec- MATTHEW ATKINSON ADAM. rolyte inthe cell. JOHN STEVENSON.

7. A cell such as claimed in claim 5 -in ALAN THOMAS MABBITT.

which the' anocle is securedto'the casing by JOHN FIELDHOUSE. 

